Dental instrument.



' l, H. MEYERS.

DENTAL INSTRUMENT.

APPLICATION HLED MAY 15. 1916.

Patented Sept. 12, 1916.

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@Nozwmyi xlli lV-Wmow l UNITED STATES PATENT JOHN HENRY MEYERS, OF GRANDISLAND, NEBRASKA.

DENTAL INSTRUMENT.

Applioation filedMay 15, 1915.

To all whom z'tmay concern Be it known that I, JOH -HENRY Mar- ERs, acitizen of the United States, residing at Grand Island, in the county ofHall and State of Nebraska, have invented certain new and usefulImprovements in Dental Instruments; andI do declare the following to beafull, clear, and exactdescript on of :the invention, such as will enableothers skilled in the art to which it appertains .to make and use thesame.

This invention relates .to' improvements in dental instruments and moreparticularly and arrangement of parts as will be hereinafter moreparticularly described and claimed.

In the accompanying drawings Figure 1 is a side elevation of aninstrument constructed in accordance with this invention with the jawsin closed position; Fig. 2 is a longitudinal section thereof; Fig. 3 isa similar view taken in a plane atrightangles to Fig. 2 .on the line 33of Fig. 2, and with-the jaws in open position; Fig.4 is

transversesection taken on the line el.4c. of

Fig. 3 Fig. 5 .is a similar view taken on.the line 5:5 of -Fi g..3;:andFig. 6 is a detail perspective view ofone of the jaws.

In the embodiment illustrated, a handle '1 is shown having a socket Qwith oppositely disposed grooves 3 therein to receive L teral retainingprojections A: on a head 5,:said projections being here shown v in theform of rectangular screw heads whichare designed for securinglongitudinallyextending plate springs 6 and 7 to sald head. These squareheads when inserted in the grooves 3 serve to hold the head againstturning relatively-t0 the handle. Thishead Specification of LettersPatent.

Patented Sept. 12,1916.

Serial 1]: 9. 97 644.

5 is shown provided with oppositely disposed openings 8 in its sidewalls in which said springsti and 7 are mounted, oneend being secured tothe head adjacent the inner end of the opening and the .otherendextendingi forwardly into the head, said forwardly projecting end ofeach spring being shown reduced and the springcurved longitudinallyoutward :to adapt the free s he of t ear 0r b y a a ns h inner endsoftoolengaging jaws .10, and 11 presently to be described.

Two parallel longitudinally extending laterally spaced arms .12 and 18project from the frontend of the head and have anopening between themwhich. communicates with the interior of the .headand through .which.extends the free endsof the springsfiand 7 Pivoted between the arms and131at .the front ends thereof are the two jaws 10 and 11 which areexactly alike in formation,

the opposed faces .of which are rectilinear throughout the greaterportion of their length and are dQSlg ne d when the jaws are in closedposition .tocontact. Thepivotsfi) whic on ect the j a the arms .1

and 13, extend-through said jawsat points spaced inwardly from their.rear ends,;said

read ends being of a length slightly less thanthe distancebetween thepivots 9 and the head 5 from which the arms extend so .35 to provideample space to permit the jaws to swing laterally between saidarrns.

One of these jaws isshown in detail in Fig. .-6 andthe inner face oredge thereof is cut away from a point slightly in advance ofthc'fulcrurn reoeivingopening 9 thereinto the rear terminal of the jaw.A shoulder 14 is .for nedat the front end of said cutaway portion, thefront corner of which is beveled for a purpose to bedescribed. The

cut-away portion of the jaw is also'inclined inwardly toward its freerear end and against which face the outwardlybent terminal,o f oneo-fthe springs is designed to engageso that whenthe jaws are assembled and'pivotally mQunted between the arms .12 and 13 of the head 5, the innerfaces of their rear terminals will be spaced some distance apart toprovide for their movement toward each other on the separation of thefront ends of the jaws by means to be described.

The free front ends of the jaws l0 and 11 are shown serrated or toothedon their outer faces to provide gripping means for engaging and securelyholding the crown or other article with which the jaws are adapted to beengaged, it being understood that the closed ends of the aws areinserted in the crown and then forced open for holding it securely inengagement with said crown.

The means for opening the jaws is shown in the form of a rod 15 having amilled operating head 16 at one end and a wedgeshaped member 17 at itsother end. This wedge-shaped member is here shown in the form of a coneand is designed to extend between the jaws 10 and 11 for forcing thefree ends thereof into open position. This rod 15 is of a lengthsufiicient to extend through the handle 1 and through the hollow head 5and to project between the rear ends of the jaws pivoted in the arms 12and 13 of said head. A portion of this rod 15 is threaded for engagementwith a threaded extension 5 formed on the rear end of the head 5 andwhen the parts are in assembled operative position, as shown in Fig. 3,the

cone-shaped wedge member 17 will be disposed between the opposed facesof the rear ends of the jaws 10 and 11 with the point of said memberextending between the inclined or beveled corners of the shoulder 14; sothat when said rod is moved forwardly, its end will be forced betweenthe jaws in advance of their pivots and thereby force the front ends ofsaid jaws open against the tension of the springs 6 and 7 which areengaged with their rear ends as will be clearly seen from Fig. 3. Whenit is desired to disengage the tool from a crown, the rod is movedrearwardly by turning the same in the opposite direction, therebydisengaging the wedge-like end 17 thereof from the jaws which willimmediately close under the action of the springs 6 and 7.

A ferrule 18 is shown arranged around the head in advance of thehandle 1to assist in connecting these parts and to protect the head against theentrance of dust or grit therein.

From the above description, it will be obvious that a neat and compacttool is formed, the parts of which may be readily assembled ordisassembled for repairing or other purposes and that to engage ordisengage the tool from the object which it is designed to hold, allthat is necessary is to turn the milled head 16 in one direction or theother for opening or closing the jaws.

By forming the beveled opposed corners or faces of the jaws in advanceof their fulcrums or pivotal points and employing in connectiontherewith the cone-shaped opening member 17, these jaws may be graduallyopened to bring their biting ends into engagement with a crown so thatwhile it will be reliably held, all danger of injuring it or changingits configuration, will be avoided.

I claim as my invention:

1. A. device of the class described com prising a pair of pivotallymounted jaws, resilient means engaging said jaws on one side of theirpivot for moving them into closed position, and a jaw opening memberoperable between them on the side of the pivot opposite to the side withwhich the closing means is engaged, whereby the jaws are forced apartagainst the tension of their closing means.

2. A device of the classdescribed comprising a head, a pair of jawspivotally mounted therein intermediate of their ends, resilient meansfor holding said jaws in closed position, and a wedge-shaped membermovable longitudinally between the jaws from the rear end thereof forengagement with their opposed faces in advance of their pivotalconnection for opening the jaws against the tension of their resilientclosing means.

3. A device of the class described comprising a head, a pair of jawspivotally mounted therein intermediate of their ends, resilient meansfor holding said jaws in closed position, and a wedge-shaped membermovable longitudinally between the jaws from the rear end thereof forengagement with their opposed faces in advance of their pivotalconnection for opening the jaws against the tension of their resilientclosing means, the

opposed faces of said jaws in adyance of their pivotal connectionconverging forwardly to receive said wedge-shaped opening member and bymeans of which the jaws may be gradually opened on the forward movementof said member.

1. A device of the class described comprising a hollow head havingforwardly extending laterally spaced parallel arms at its front end andan internally threaded extension at its rear end, jaws pivotally mountedintermediately of their ends between said arms, springs carried by saidhead and mounted between the rear ends of said arms for forcing themapart and their front ends into closed position, and a rod havingthreaded engagement with the extension at the rear end of said head andprovided with a wedge-like member for insertion between said jaws inadvance of their pivotal connection whereby their front ends areforcibly separated against the tension of their springs.

5. In a device of the class described, a handle having a bore extendinglongitudinally therethrough and enlarged at its front end to form asocket, said socket having opopening member movable longitudinally inpositely disposed grooves in its side walls, said handle and head, andactuating means a hollow head havlng a tubular extension at for saidmember. its rear end for insertion in said socket, piv- In testimonywhereof I have hereunto set 5 oted jaws carried by said head, springsnormy hand in presence of two subscribing Wit- 15 mally closing saidjaws, attaching screws for nesses.

said springs having angular heads for en- JOHN HENRY MEYERS. gagementwith the grooves of said handle Witnesses: socket whereby said head isheld against BENJAMIN J. CUNNINGHAM,

l0 turning relatively to said handle, a jaw MABELL F. WINANS.

Copies of this patent may he obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

